Are you running it with punkbuster enabled? if so try shutting it off just to see what happens. I bought my Q3 cds from ebay and for some reason PB wants to act like a ass on ocassion. Personally my relationship is love hate with PB as yeah it stops some hacks but not all hacks but it also causes my game to go apeshit by throwing various error flags including misstyped cd key and booting me from servers for no reason. So I never run it myself.